feat: add customizable upgrade message on client/server version mismatch (#11587)

coderd/apidoc/docs.go

@@ -8329,6 +8329,10 @@ const docTemplate = `{
                     "description": "ExternalURL references the current Coder version.\nFor production builds, this will link directly to a release. For development builds, this will link to a commit.",
                     "type": "string"
                 },
+                "upgrade_message": {
+                    "description": "UpgradeMessage is the message displayed to users when an outdated client\nis detected.",
+                    "type": "string"
+                },
                 "version": {
                     "description": "Version returns the semantic version of the build.",
                     "type": "string"
@@ -9043,6 +9047,9 @@ const docTemplate = `{
                 "cache_directory": {
                     "type": "string"
                 },
+                "cli_upgrade_message": {
+                    "type": "string"
+                },
                 "config": {
                     "type": "string"
                 },

coderd/apidoc/swagger.json

@@ -7418,6 +7418,10 @@
           "description": "ExternalURL references the current Coder version.\nFor production builds, this will link directly to a release. For development builds, this will link to a commit.",
           "type": "string"
         },
+        "upgrade_message": {
+          "description": "UpgradeMessage is the message displayed to users when an outdated client\nis detected.",
+          "type": "string"
+        },
         "version": {
           "description": "Version returns the semantic version of the build.",
           "type": "string"
@@ -8079,6 +8083,9 @@
         "cache_directory": {
           "type": "string"
         },
+        "cli_upgrade_message": {
+          "type": "string"
+        },
         "config": {
           "type": "string"
         },

coderd/coderd.go

@@ -645,7 +645,7 @@ func New(options *Options) *API {
 		// All CSP errors will be logged
 		r.Post("/csp/reports", api.logReportCSPViolations)
 
-		r.Get("/buildinfo", buildInfo(api.AccessURL))
+		r.Get("/buildinfo", buildInfo(api.AccessURL, api.DeploymentValues.CLIUpgradeMessage.String()))
 		// /regions is overridden in the enterprise version
 		r.Group(func(r chi.Router) {
 			r.Use(apiKeyMiddleware)

coderd/deployment.go

@@ -68,7 +68,7 @@ func (api *API) deploymentStats(rw http.ResponseWriter, r *http.Request) {
 // @Tags General
 // @Success 200 {object} codersdk.BuildInfoResponse
 // @Router /buildinfo [get]
-func buildInfo(accessURL *url.URL) http.HandlerFunc {
+func buildInfo(accessURL *url.URL, upgradeMessage string) http.HandlerFunc {
 	return func(rw http.ResponseWriter, r *http.Request) {
 		httpapi.Write(r.Context(), rw, http.StatusOK, codersdk.BuildInfoResponse{
 			ExternalURL:     buildinfo.ExternalURL(),
@@ -76,6 +76,7 @@ func buildInfo(accessURL *url.URL) http.HandlerFunc {
 			AgentAPIVersion: AgentAPIVersionREST,
 			DashboardURL:    accessURL.String(),
 			WorkspaceProxy:  false,
+			UpgradeMessage:  upgradeMessage,
 		})
 	}
 }